Did I goof??? *LOL*

A couple of months ago I disconnected the battery in the '91 coupe q, so
that my insurance company would consider it to be in long-term storage.
This morning, after connecting the battery, when I open the door the horn
goes off for a few seconds, and when I turn the key to the "On" position the
horn blares continuously.
Could disconnecting the batter have enable an anti-theft scheme?
TIA!
~ Doug
PS - The engine will NOT turn over....